DE 195 12 480 A1 discloses thermally activated catalysts for making polyurethane foam comprising compounds of the structure EQU .sup.-O.sub.2 C--X--C(O)--NH--Y--NHR.sub.1 R.sub.2.sup.+
where X is a C2-C3 .alpha.,.omega.-alkylene group, 1,2-substituted cyclohexyl group or ortho-substituted phenylene group; Y is a C2-C6 alkylene group which may contain heteroatoms; and R.sub.1 and R.sub.2, which may be the same or different, are C1-C20 alkyl groups which may contain oxygen atoms or together with the tertiary nitrogen form a 5 or 6 member ring which may contain oxygen atoms.